It should be noted that the NLF in the middle step of the process (insets \(c\)  and \(d\) ) corresponds to a similar picture to the recent one discussing the formation of alpha-particles during the fission process [1]}: NLF close to 1, with non-localized density, at value below the saturation one. This would mean that during the fission process, delocalized 4-nucleons overlap could be formed and detected, but maybe not as compact alpha clusters, as there are no alpha clusters on the predicted density profiles. It also shows the two-step process: when the nucleonic density emerges in an empty location, first the NLF can have value close to 1, meaning that a pure overlap of 4 nucleons could be detected there. In a possible, but not systematic, second step, the density increases and eventually reach the saturation density, corresponding to the presence of the 4 nucleons of a spatially localized and bound alpha-particle. But this second step may not always be reached, as indicated by the density plots of Ref. [1]}, which remain below the saturation density and show no localization at the positions where C\(_{q\sigma }\) =1.
